b2

By establishing memory cells that produce antibodies quickly on reinfection

1 of 35

Why do people react differently to drugs and vaccines?

Genetic differences

2 of 35

What is part of the immune system and how do they destroy microorganisms?

White blood cells are part of the body's immune system and can destroy microorganisms by engulfing and digesting them or by producing antibodies

3 of 35

How does antimicrobial resistance develop?

Random changes in the genes of microorganism sometimes lead to varieties which are less affected by antimicrobials

4 of 35

What causes the symptoms of an infectious disease?

Damage done to cells by microorganisms or the toxins they produce

5 of 35

How do antibodies recognise microorganisms?

By the antigens that they carry on their surface, each different microorganisms have different antigens and therefore a different antibody is needed to recognise each different type of microorganism

6 of 35

How are epidemics of infectious disease prevented?

It is necessary to vaccinate a high percentage of a population so there are fewer people to pass it on

7 of 35

Define antibiotics

A type of antimicrobial that are effective against bacteria but not viruses

8 of 35

What can microorganisms develop over a period of time?

Bacteria and fungi may become resistant to antimicrobials

9 of 35

What is the importance of long term human trials?

It might take a long time for the effect it was designed for to be seen or for side effects to be seen

10 of 35

What does a vaccine usually contain?

A safe form of a disease causing microorganism

11 of 35

In what conditions can microorganisms reproduce rapidly?

In sustainable conditions such as those inside a human body, microorganisms can reproduce rapidly to produce very large numbers

12 of 35

How can antibiotic resistance be reduced?

We should only use antibiotics when necessary and always complete the course

13 of 35

How does immunity develop?

Once the body has made the antibody to recognise a particular microorganism, memory cells can make that antibody again very quickly, therefore protecting against that particular microorganism in the future

14 of 35

Why are vaccines and drugs never completely risk free?

Individuals have varying degrees of side effects to them

15 of 35

Define antimicrobials

Chemicals called antimicrobials can be used to kill bacteria, fungi and viruses

16 of 35

What are new drugs and vaccines first tested on and tested for?

First tested on animals and human cells grown in the laboratory for safety and effectiveness

17 of 35

Explain the three types of human trials

1. Open label trial; both scientist and patient know what treatment is given. - 2. Blind trial; patient does not know what treatment they are given but scientist does. - 3. Double blind trial; scientist & patient doesn't know the treatment

18 of 35

What are the ethical issues related to using placebos in human trials?

People think its unethical to give seriously ill patients placebos as they are not getting the potential benefits of the new drug

19 of 35

Who are human trials carried out on and what for?

On healthy volunteers to test for safety then people with the illness to test for safety and effectiveness

20 of 35

How do you calculate population growth of microorganisms?

Ensure total time microorganism is reproducing for is in mins. Divide total time it is reproducing for by the time it takes to reproduce once. Starting number bacteria x 2 & keep x 2 answers for how many reproductory periods

21 of 35

What do control systems have?

Receptors to detect changes in the environment. Processing centres to receive information and coordinate response automatically & effectors to produce the response

22 of 35

Which 2 communication systems are involved in homeostasis?

Nervous and hormonal communication systems

23 of 35

Why is balanced water level important?

For maintaining the concentration of cell contents at the correct level for cell activity

24 of 35

What is negative feedback?

Reverses any changes to the system's steady state

25 of 35

What is homeostasis?

Maintaining a constant internal environment

26 of 35

What affects the concentration of urine?

External temperature, exercise level and intake of fluids and salt

27 of 35

What is the role of the kidneys?

Balancing levels of water, waste and other chemicals in the blood

28 of 35

How do the kidneys balance water levels?

By producing dilute or concentrated urine

29 of 35

What needs to be balanced to control water levels?

Water levels are controlled by balancing gains from drinks, food and respiration and losses through sweating, breathing, faeces and the excretion of urine

30 of 35

Explain how alcohol affects the production of urine?

Suppresses the production of ADH, so the kidneys reabsorb less water. A larger volume of more dilute urine is produced. As more water is lost in urine this can lead to dehydration & be harmful to health

31 of 35

Explain how ecstasy affects the production of urine?

Increases the production of ADH so the kidneys reabsorb more water. A smaller volume of less dilute urine is produced

32 of 35

Explain what happens when there is too much water in the blood?

The brain detects too much water in blood. Pituitary gland releases less ADH. Kidneys reabsorb less water so more water is lost in urine. Blood water level returns to normal

33 of 35

What is concentration of urine controlled by and where is it released from?

Controlled by a hormone called ADH which is released into the bloodstream by pituitary gland

34 of 35

What do automatic control systems throughout the body do and why?

Maintain a range of factors at steady levels and that this is required for cells to function properly